Systems for the Automotive Industry for Improved Safety of Pregnant Occupants
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This item was submitted to Loughborough’s Institutional Repository (https://dspace.lboro.ac.uk/) by the author and is made available under the following Creative Commons Licence conditions. For the full text of this licence, please go to: http://creativecommons.org/licenses/by-nc-nd/2.5/ Systems for the Automotive Industry for Improved Safety of Pregnant Occupants by Alix Mary Weekes (BEng hons) A Doctoral Thesis Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University June 2010 © Alix Mary Weekes 2010 Abstract ABSTRACT The thesis presents an investigation of pregnant women’s safety and comfort needs during car travel. A survey is used to investigate all aspects and problems of car travel. This survey is a comprehensive examination of the entire driving activity with much detail of reported difficulties from pregnant women that forms a novel resource for the automotive engineers. The survey results are used to generate guidelines for the automotive industry. A series of sled tests are presented that investigate seat belt use in pregnancy including the use of lap belt positioners. The peak abdominal pressure results clearly agree with current guidelines that the lap belt should be positioned across the hips and not across the abdomen. This research includes a novel anthropometric dataset for 107 pregnant women including measurements especially selected for the field of automotive design and to describe the changes of pregnancy. This includes investigation of pregnant driver’s proximity to the steering wheel. A novel measurement of ‘knee splay’ is used to define the pregnant women’s preference to sit with their knees widely spaced instead of knees together, in both normal sitting and in a car. Comparison is made between the pregnant women’s measurements and the available data in the literature for non- pregnant women and males, and this shows that pregnant women can be excluded from designs if the accommodation does not consider their needs. The pregnant women’s anthropometric data is presented as a novel website in order to make the data available to the automotive industry. This website is generated for use by automotive engineers and is designed to suit their usability needs and the general trends within the industry, in order to make the site more user-friendly and more likely to be used as a reference for pregnant occupant’s needs. ii Acknowledgements ACKNOWLEDGEMENTS I would like to acknowledge the support and patience of my supervisor, Professor. B. Serpil Acar, to whom I am grateful for the continued encouragement. I also gratefully acknowledge the funding provided by the Department of Computer Science at Loughborough University. The “Automotive Design: Incorporating the Needs of Pregnant Women” project was funded by the EPSRC (Engineering and Physical Sciences Research Council, UK) GR/R13081 research grant of the Innovative Manufacturing and Construction Research Centre. I am also grateful to Thatcham for the funding provided in support of this thesis, and to Matthew Avery for his support. I thank Mr. Malcolm Griffiths of the Luton and Dunstable Hospital NHS Trust for his assistance. I also thank my colleagues and friends from both Loughborough University and Thatcham. I would like to thank all the volunteers who have given their time for measurements and questionnaires, without whom this research would have been impossible. In particular I appreciate the time given by my sister Katie Davis, and by my cousin Lisa Lane, both of whom were extremely helpful with refining the anthropometric measurement procedures. I also thank Katie Davis for allowing the use of her photograph throughout this thesis. I am grateful to my loving family for their support, in particular my parents for their gentle backing and belief in me. I would like to thank Matthew Edwards for his patience, encouragement, and support. iii Table of Contents CONTENTS Abstract..........................................................................................................................ii Acknowledgements...................................................................................................... iii List of Figures...............................................................................................................xi List of Tables ..............................................................................................................xvi List of symbols and Abbreviations ............................................................................xvii Glossary of obstetric Terms..................................................................................... xviii CHAPTER 1: INTRODUCTION .........................................................1 1.1 AIMS OF THE RESEARCH.........................................................................1 1.2 OBJECTIVES OF THE RESEARCH..........................................................1 1.3 THESIS OUTLINE ........................................................................................2 CHAPTER 2: LITERATURE REVIEW................................................3 2.1 AUTOMOTIVE SAFETY NEEDS OF PREGNANT WOMEN................3 2.1.1 Pregnant women’s anthropometric data ..............................................4 2.1.2 Collisions involving pregnant women ...................................................8 2.1.3 Fetal fatality and injury risk..................................................................9 2.1.3.1 Injury mechanisms ..........................................................................9 2.1.3.2 Injury risk and seat belt use ..........................................................12 2.1.3.3 Seat belt usage in pregnancy ........................................................15 2.1.3.4 Education about correct seat belt use...........................................17 2.1.4 Legal requirements and guidelines regarding pregnant women’s safety................................................................................................................20 2.1.5 Other issues of car travel in pregnancy ..............................................22 2.1.5.1 Proximity to the steering wheel.....................................................22 2.1.5.2 Vehicle entry and exit....................................................................23 iv Table of Contents 2.2 HCI AND WEB USABILITY FOR AUTOMOTIVE ENGINEERS AND DESIGNERS .......................................................................................................24 2.2.1 Human Computer Interaction (HCI) and web usability...................24 2.2.2 The automotive design process ............................................................29 2.2.3 Characteristics of automotive engineers and designers ....................38 2.2.4 Review of existing software for automotive designers and engineers ..........................................................................................................................43 2.2.4.1 PeopleSize .....................................................................................43 2.2.4.2 ARIS ..............................................................................................44 2.2.4.3 MADYMO .....................................................................................44 2.2.4.4 PC-Crash ......................................................................................45 2.2.4.5 Beltfit.............................................................................................45 CHAPTER 3: DATA COLLECTION OF SAFETY AND COMFORT ISSUES FOR PREGNANT WOMEN .........................46 3.1 PREGNANCY AND DRIVING QUESTIONNAIRE ...............................46 3.1.1 Pregnant driver survey.........................................................................47 3.1.2 Online method .......................................................................................48 3.1.3 Sample of pregnant women..................................................................48 3.1.3.1 Sampling method and representivity.............................................49 3.2 DRIVING AND SAFETY ............................................................................51 3.3 SEAT BELTS................................................................................................53 3.3.1 Legal requirements and guidelines for seat belt usage during pregnancy........................................................................................................53 3.3.2 Safety and comfort issues for pregnant women using seat belts ......53 3.3.2.1 Use of the seat belt........................................................................53 3.3.2.2 Positioning of the seat belt............................................................53 3.3.2.3 Problems using the seat belt .........................................................55 3.3.2.4 Awareness of seat belt safety ........................................................57 3.3.3 Seat belt positioners ..............................................................................57 3.4 AIRBAGS ......................................................................................................57 3.4.1 Guidelines for vehicle airbags during pregnancy ..............................57 3.4.2 Airbag safety and comfort issues for pregnant women.....................58 v Table of Contents 3.5 VEHICLE ENTRY & EXIT........................................................................60 3.5.1 Discussion of pregnancy related changes............................................62